ObjectsMemento

Saves and restores a snapshot of the visual state of the Entity's that represent objects within a Scene.

• An Entity represents an object when Entity#isObject is true.
• Each object-Entity is registered by Entity#id in Scene#objects.

See Also

• CameraMemento - Saves and restores the state of a Scene's Camera.
• ModelMemento - Saves and restores a snapshot of the visual state of the Entity's of a model within a Scene.

Usage

In the example below, we'll create a Viewer and use an XKTLoaderPlugin to load an .xkt model. When the model has loaded, we'll hide a couple of Entitys and save a snapshot of the visual states of all the Entitys in an ObjectsMemento. Then we'll show all the Entitys again, and then we'll restore the visual states of all the Entitys again from the ObjectsMemento, which will hide those two Entitys again.

import {Viewer, XKTLoaderPlugin, ObjectsMemento} from "xeokit-sdk.es.js";

const viewer = new Viewer({
    canvasId: "myCanvas"
});

// Load a model
const xktLoader = new XKTLoaderPlugin(viewer);

const model = xktLoader.load({
    id: "myModel",
    src: "./models/xkt/schependomlaan/schependomlaan.xkt"
});

model.on("loaded", () => {

     // Model has loaded

     // Hide a couple of objects
     viewer.scene.objects["0u4wgLe6n0ABVaiXyikbkA"].visible = false;
     viewer.scene.objects["3u4wgLe3n0AXVaiXyikbYO"].visible = false;

     // Save memento of all object states, which includes those two hidden objects
     const objectsMemento = new ObjectsMemento();

     objectsMemento.saveObjects(viewer.scene);

     // Show all objects
     viewer.scene.setObjectsVisible(viewer.scene.objectIds, true);

     // Restore the objects states again, which involves hiding those two objects again
     objectsMemento.restoreObjects(viewer.scene);
});
`

Masking Saved State

We can optionally supply a mask to focus what state we save and restore.

For example, to save and restore only the Entity#visible and Entity#clippable states:

objectsMemento.saveObjects(viewer.scene, {
    visible: true,
    clippable: true
});

//...

// Restore the objects states again
objectsMemento.restoreObjects(viewer.scene);